Semiconductor device and manufacturing method therefor

Abstract

To cover a conductive interconnection (2) of a semiconductor device (1) at high speed with an insulating film (3) having good step coverage, a conductive dummy pattern (8) is provided around the interconnection (2) in spaced relationship therewith. The dummy pattern (8) and interconnection (2) are then covered with insulating film 3 using the bias sputtering method. The dummy pattern (8) and interconnection (2) are preferably applied simultaneously to the substrate using a single mask.

I claim: 
     
       1. A semiconductor device comprising: a conductive interconnection film formed on a predetermined region of a semiconductor substrate,   a dummy pattern formed round the outer periphery of said conductive interconnection film, said dummy pattern being formed of conductive film out of electrical contact with the interconnection film, and   a bias sputtered insulating film formed on said semiconductor substrate to cover said conductive interconnection film and said dummy pattern, said bias sputtered insulating film having substantially flat surfaces overlying both the interconnection film and portions of the substrate surrounding the interconnection film and inclined flat surfaces overlying the dummy pattern and intersecting said other flat surfaces.   
     
     
       2. A semiconductor device according to claim 1, wherein said conductive dummy pattern is formed spaced from said conductive interconnection film and out of physical contact therewith. 
     
     
       3. A semiconductor device according to claim 1, wherein said conductive dummy pattern is formed of a metal or a metal alloy. 
     
     
       4. A semiconductor device according to claim 1, wherein said conductive dummy pattern is formed of an aluminum or an aluminum alloy. 
     
     
       5. A semiconductor device according to claim 1, wherein said dummy pattern is formed around the outer periphery of a conductive interconnection film whose width is more than twice the thickness of an insulating film to be formed thereon. 
     
     
       6. A semiconductor device according to claim 2, wherein said dummy pattern and conductive interconnection film are formed within the same plane on the substrate and of the same conductive material and have substantially the same thickness. 
     
     
       7. A semiconductor device comprising: a conductive interconnection film formed on a predetermined region of a semiconductor substrate;   a dummy pattern formed around the outer periphery of the conductive interconnection film and out of physical contact therefrom, said dummy pattern being formed of conductive film and thereby out of electrical contact with the interconnection film;   a bias sputtered insulating film formed on said semiconductor substrate to cover said conductive interconnection film and said dummy pattern.   
     
     
       8. The semiconductor device of claim 6, further comprising a second conductive interconnection film formed on said bias sputtered insulating film and overlying the dummy pattern and first conductive interconnection film. 
     
     
       9. A semiconductor device comprising: a conductive interconnection film formed on a predetermined region of a semiconductor substrate,   a dummy pattern formed around the outer periphery of said conductive interconnection film, said dummy pattern being formed of conductive film out of electrical contact with the interconnection film said interconnection film being formed within the same plane on the substrate as and of the same conductive material and thickness as the dummy pattern, and   a bias sputtered insulating film formed on said semiconductor substrate to cover said conductive interconnection film and said dummy pattern, said bias sputtered insulating film having substantially flat surfaces overlying both the interconnection film and portions of the substrate surrounding the interconnection film and inclined flat surfaces overlying the dummy pattern and intersecting said other flat surfaces.   
     
     
       10. A semiconductor device comprising: a conductive interconnection film formed on a predetermined region of a semiconductor substrate;   a dummy pattern formed around the outer periphery of the conductive interconnection film and out of physical contact therefrom, said dummy pattern being formed of conductive film and thereby out of electrical contact with the interconnection film;   a bias sputtered insulating film formed on said semiconductor substrate to cover said conductive interconnection film and said dummy pattern,   said interconnection film and said dummy pattern being formed within the same plane on the substrate and of the same conductive material and thickness.